Tests for migratory history of the New Zealand common smelt (Retropinna retropinna (Richardson)) using otolith isotopic composition

Abstract– Stable oxygen and carbon isotopic analyses were made for water at 24 sites, mainly from the Waikato watershed (North Island, New Zealand), and for carbonate from fish sagittal otolith material at each of the sites, mainly from the common smelt ( Retropinna retropinna (Richardson)), to test their potential use in identification of resident and anadromous/migratory stocks suggested in an earlier pilot study. Results provide strong evidence that ¹⁸O is precipitated in otoliths close to isotopic equilibrium with rearing waters. The smelt rearing and residency waters examined have characteristic oxygen and carbon isotopic 'signatures', and the ¹⁸O composition of the smelt otoliths mirrors this within about 1%0, making it possible to use the technique for determining resident and/or migrant history of the fish. The ¹³C otolith composition, though usually tracking that of probable rearing and/or residency waters, has a larger and more variable offset, possibly of metabolic origin, making its use less reliable as a habitat signature.     

Incorporation of environment and feed quality into a net energy model for beef cattle

The California net energy system has gained wide acceptance as a method for predicting rates of gain in growing and finishing beef animals. Researchers at the University of Kentucky, in co-operation with agricultural scientists in two regional research projects, NC-114 and S-156, have developed an interactive model that enhances the usefulness of the net energy system by including skeletal size, feed quality, temperature and relative humidity to determine feed intake and utilisation. Basically, the intake based on feed availability, nutrient composition, potential skeletal size and heat loss potential. After the feed is consumed, it is utilised according to the productive status of the animal, i.e. growth, lactation, foetal development, etc., using a modified form of the net energy system to predict weight change.The model allows a researcher to easily modify environment, feed, breed characteristics and productive status so as to evaluate their influence on the performance of the animal.     

Immunohistochemical localization of IgG1 and IgG2 in prepartum and lactating bovine mammary tissue

The differential distributions of IgG1 and IgG2 were determined in prepartum and lactating bovine mammary tissue by indirect immunofluorescence. IgG1 was found predominately within the alveolar epithelial cells and lumens of prepartum tissue whereas IgG2 was largely confined to the stromal area surrounding the alveoli. Both IgG subclasses were confined predominately to the stroma in lactating tissue. Few IgG containing stromal cells were readily distinguished in any of the mammary tissue used in this study.     

Physical analysis of rockwool slabs and effects of fiber orientation,irrigation frequency and propagation technique on chrysanthemum production 1

Chrysanthemum X morifolium ’Bright Yellow May Shoesmith’ was grown as a cut flower crop in rockwool slabs in various methods to test different cultural and rockwool options. Direct planting of unrooted and calloused cuttings led to deleterious water stresses in spite of a commercially prohibitive input of labor for syringing. Planting of partially rooted cuttings was successful in terms of flower production but required excessive labor. Satisfactory and equal results were obtained from 1) inserting cuttings rooted in rockwool cubes into the slab such that the cube top was either flush or 1.3 cm above the slab surface, 2) applying nutrients 1 or 3 times per day, and 3) a horizontal or verticle fiber orientation in the slab. Nutrient accumulation in plants of all treatments were in satisfactory ranges and did not account for observed differences in growth.